Friday, 25 December 2015

Not wishing to contend with an evening of dire XYL style Christmas TV (Strictly Come Dancing, Call the Midwife and Downton Abbey) I escaped into the shack and decided to repair my Vectronics VC300DLP Antenna Tuner. I got this ATU second hand last year and while it has been serviceable it had become temperamental of late. The units rotary inductor switch had become stiff and suddenly I was unable to match the OCFD on some bands so it had clearly broken.

I had a 12-position switch (rated at 5A) and knob, originally sourced for an abandoned project and hoped it would be suitable. The existing switch knob on the ATU wasn't an original, I'd assumed it had replaced one lost or broken. When I removed the cover it was clear that the whole switch had already been changed at sometime.

I also noticed a prominent burn mark inside the inductor coil, caused by a clear break in the insulation of the wire which was resting on the grounded bottom plate.

I know the previous owner of the ATU has a 300W RM BLA-350 linear amplifier, whereas I only normally operate around 30W maximum at my QTH, so not sure how much of this arcing I had caused but it needed sorting! A little over half an hour with the soldering iron and I had replaced the switch and slipped some heat shrink over the broken insulation and re-soldered the wire, lifting it off the ground plate.

The ATU seems to work well, now fitted with a new knob (just missing a cap at the moment) the switch turns nicely. I also cleaned up the SO-239 connectors on the back as they were tarnished and oxidised. I used a small bit of contact cleaner on some cotton buds to clean up the threads and the centre pins, removing a surprising amount of crud. The patch and antenna leads now screws on much better.

With the Mother--in-law staying with us over the festive period I suspect I may be in the shack quite a bit, I have plenty of jobs and half finished projects to keep me busy!

Tuesday, 22 December 2015

As a birthday present to myself I have just ordered a Retevis RT3 DMR hand-held off eBay which should be delivered just after Christmas.

South Kesteven ARS had a talk in October by Sean Burton 2E0ENN about amateur DMR where he demonstrated some handsets and the new DV4Mini which allows gateway and internet linking for the various networks, DSTAR, DMR and System Fusion. This piqued my interest in the DMR scene.

As I posted last time I dabbled a few years ago with decoding PMR DMR using software and a sound card but they were very hit and miss at the time. I reacquainted myself with the various projects and using the FUNCube Dongle Pro+ and the latest version of DSDPlus (support forum at RadioReference.com) monitored the nearby GB7RR DMRPlus repeater managing to get some reasonably clear decodes of some amateur transmissions.

I decided to dig out my Realistic PRO-2022 scanner and using a discriminator tap fed into the sound card got slightly better quality decodes.

Doing some research and reading a couple of reviews had decided I was going to get a Tytera TYT MD-380 when funds allowed but spotted the Retevis RT3 which appears to be identical and slightly cheaper.

I know some people wince at the thought of DMR and issues with proprietary technology used in some of the systems but I think the genie is out the bottle and it isn't going away soon. Adoption of DMR appears to be growing with talk of restructuring of talk groups needed to deal with the growth (whatever that means!) so I should at least get my feet wet and understand the technology.

I registered for an ID, now off to decode the jingo and understand all this talk of codeplugs, talk groups and time slots.

Friday, 20 November 2015

Here I am a month after the last post and it is has been a month of very little 'radio antics'.

I was acutely aware that since the end of September my wife had become a radio widow so promised not to lock myself away in the shack for a while and have been doing some much needed painting and decorating around the house.

I haven't been in much of a radio mood anyway as I have been unwell and am still not fully over my last wobble. Band and weather conditions have been rubbish with a sustained period of high wind and rain including storms Abigail and Barney. As a precaution I dropped the pole and it became apparent I had some maintenance to do on the OCFD.

The shack too had been in need of some sorting out, which I thankfully I did muster enthusiasm to tidy up.

While being largely uninspired I haven't been completely radio silent, I did get on air for the South Kesteven ARS 2m net but found myself suffering some QRM again

It isn't the first time I've seen this sort of signal, but I had thought it had gone away, it seems it is back and stronger! This was an ARISS contact I monitored back in 2013 before I was licensed with a similar noise.

After using the SDR to identify the noise I realised I have been neglecting the FUNCube Dongle for far too long. So ordered some new SMA adapters from HamGoodies and pressed it back into service. I have been using it to decode the telemetry from the FOX-1A (AO-85) satellite with the updated software and have now got myself on the leader board even if the collinear is currently horizontal about four feet off the ground!

I remembered I dabbled a few years ago with decoding PMR DMR using the SDR and a scanner with a discriminator tap using various programs but they were very hit and miss at the time. I reacquainted myself with the various projects and had a go at decoding some amateur transmissions.

I downloaded the latest program called DSDPlus (support at RadioReference.com) and monitoring the nearby GB7RR DMRPlus repeater managing to get some clear decodes with little effort.

Finally this week I gave a presentation at SKARS on the subject of HABs and how to plan a HAB launch. Following on from the Eggsplorer-1 and Hamfest "Pigs In Space" HAB launch I decided to try to explain everything I had learned for anyone else contemplating giving it a go!

It was a long talk (perhaps too long) as I covered everything from building the electronics, software, making the payload box, getting the right balloon, parachute, gas, obtaining permission and then the prediction, launching tracking and recovery.

Sunday, 18 October 2015

What a difference a week makes, last week I was feeling somewhat low and as a result ducked out of the RSGB convention as I wasn't feeling very sociable.

But this week I had to get my head straight since the South Kesteven ARS (of which I am Chairman) were involved for the second year in the Scouting Jamboree on the Air (JOTA) weekend operating GB5FSG for the 1st Foston Scouts.

But before that we were also involved with another local scouting group, the 1st Barrowby where we assisted in a class of 12 Cubs with their communication badge.

Together with Stewart (M0SDM), Sean (2E0ENN) and Konrad (2E0KVF) we spent an evening giving them a introduction to amateur radio. Konrad who is an ex-scout leader explained the hobby, Stewart and Sean helped them pass messages via a radio. There was also a timely visible pass of the International Space Station during the evening and I hoped they might be able to see it while I demonstrated transmitting APRS messages via the onboard digipeater.

Using my new dual band Yagi, laptop and FT857D in the boot of my car I did successfully get messages digipeated and igated however the cloud and rain prevented the cubs seeing the ISS pass overhead (I put the coordinates in slightly wrong, so are shown slightly south of where we were)

The evening was a great success and the enthusiasm shown by the Scout leaders hopefully means SKARS will be involved in more activities for the Barrowby Scout group. Interestingly we were not the first local club they approached to assist but after they were given the cold shoulder by them we were happy to take up the challenge. The Barrowby group were also interested in being involved in the Jamboree on the Air (JOTA) next year.

So on to the main event this week, the GB5FSG JOTA station, operated by Stewart, Sean and myself. It is exactly a year since I gained my full licence and this was my first Notice of Variation for a special event station, last year under the previous chairman we had run GB2FFC with some success but this year we hoped to improve the experience for the Cubs/Beavers and Scouts.

Firstly we had a much improved antenna installation, with Stewart's Land Rover and impressive pushup mast we had an excellent OCFD dipole, resonant on several bands including 40m along with another smaller pole holding up an end fed long wire for the datamode station. We also put up a collinear for a 2m VHF station.

Last year we were hampered by the noise of excitable children in the main room of the scout hut which made operating and hearing contacts difficult. This year we asked for some separation from the hubbub and had planned to use a tent. Instead we setup in the storage area in the back of the hut which proved ideal as it allowed us to control the number of children and allowed easier working conditions - it was a little chilly but much warmer than a tent would have been.

On Saturday we used Stewart's FT897 as the main HF rig, Sean operated a 2m meter station with a number of contacts. Like last year I had my FT857 operating a datamode (primarily PSK) but a damaged feeder issue curtailed this for most of the day and we soon concentrated on the HF SSB voice contact as conditions were good and the band was busy with other JOTA stations.

In keeping with the aims of JOTA we didn't chase numbers instead we had some lengthy quality contacts, including a marathon 30 minute plus contact with I believe was GB2WSG the 2nd Wellington Scout Group with lots of two-way greeting messages being sent to really give the children a full experience of using the radio.

The day before I had quickly constructed a Morse code oscillator (since I didn't have one) using an arduino board and an old computer speaker for added volume and this proved popular as the children tapped out their own names, their friends names, call signs, their ages and various words.

I had created some certificates and stickers to reward the children and to prove they had completed the tasks should they need them for any future scouting badges and awards.

Sunday we just operated for the morning and since Stewart couldn't attend I brought along my FT450D and Sean and myself operated on HF SSB. Sadly my poor Morse oscillator failed quite spectacularly in a puff of smoke but all was not lost as again conditions were excellent and we were able to pass lots of greeting messages again. I haven't used the FT450D in anger so it was excellent to let it stretch its legs and the audio and DSP proved excellent in dealing with the QRM from the contest running at the same time.

Working with the Scouts this week has really was a therapeutic exercise for my soul and made me glad I got licenced and was able to get involved with this. I am not naturally comfortable with children, since I am not a parent. But it was rewarding seeing the look of wonder on some of their faces as they passed messages.. like it was magic ;-)

Saturday, 10 October 2015

This time last year I was preparing to take my advanced licence exam at the RSGB Convention (which I passed) and I vowed to attend this years convention proper.

Unfortunately I have a had a bit of a wobble emotionally and despite having booked day tickets I have decided at the last minute not to attend.

The past few weeks have had plenty of euphoric moments, with the successful flight of my the high altitude balloon at the recent hamfest and my first satellite QSO however following these highs I have suddenly found myself in a bit of a low, this is due to a number of factors.

This isn't the first time I have been in one of these dark moods. Sadly apart from my hobby, which has become a crutch I realise I am again stuck in a rut and I know I have to make a number of major decisions to put things back on track.

Wednesday, 7 October 2015

Sunday I took part in my first RAYNET event at the Walk for Parkinson's at Burghley House in Lincolnshire. This was a sponsored walk to raise money for Parkinson's UK a research and support charity working to help find a cure and improve life for those affected by Parkinson’s disease.

Starting at the Burghley House stately home, participants could chose to do either a gentle 3 mile stroll within the grounds or a more challenging 10-mile walk out of the park and through the Barnack Hills and Holes National Nature Reserve.

RAYNET's task was to provide communication support to the organisers with operators situated around the course at various marshalling points to pass messages and if necessary request assistance.

Earlier in the year there was a presentation about the work of RAYNET at the South Kesteven ARS by Jim Wheeldon (M0JHW) and Alan Clarke (M0NLR) after which I'd offered my services for future events, so when Jim called me and asked for some help I was happy to oblige.

My task was quite straightforward, simply manning one of the marshal points along the course directing the walkers and making sure they were happy and injury free, if not I was to call for assistance. Despite being under the weather for the last few days with a bad head cold and a painful sore throat I still turned out and really enjoyed helping.

It was nice to use my radio licence and equipment for something useful, spending a pleasant morning in the sunshine talking to the walkers and some local residents explaining all about amateur radio.

RAYNET was formed back in the 1950s following the East Coast floods to provide a way of organising the valuable resource that Amateur Radio is able to provide to the community. While it is called the Radio Amateurs’ Emergency Network the majority of its work nowadays is to provide support to community events, like the sponsored walk.

However it can still be called up to offer assistance at incidents such as the recent Shoreham Airshow plane crash. The South Sussex RAYNET group, assisted by members of South Kent RAYNET, were already providing communications support for the organisers and the user
services at the airshow when the Hawker Hunter aircraft crashed into vehicles on the A27 during a flying display.

It was reported that following the crash the area was in lock down in four hours and it the demand on the local mobile networks by concerned spectators, residents and residents outstripped capacity making normal communication difficult. RAYNET operators were able to provide much needed support in the aftermath.

Abdel explained all the current active satellites, how to work through them and gave hints and described techniques for achieving success on this more challenging mode of operation.

Spurred on I opted to target the SO-50 satellite which until very recently this was the only satellite carrying a FM transponder. The satellite receives on 145.850 MHz and retransmits them on 436.800 MHz (+/- 10
kHz Doppler shift). Operation requires the use of CTCSS (PL) tones of 74.4 Hz which starts a 10 minute timer and then a 67
Hz tone used for the contact. More details of how to operate and a video are on the AMSAT-UK website

I initially tried using just a suitably programmed Baofeng UV-5R with a NA771 whip and could clearly hear the downlink on higher passes, I called a few times with no luck.

I hadn't monitored SO-50 much before and sadly it seems to suffer from very poor operating, with stations calling over contacts in progress, or stations continually calling CQ CQ seemingly oblivious to any reply and those that just keep calling "hola hola hola" for whatever bizarre reason! I would be lucky to get through the QRM with just the whip so I needed a better antenna.

Despite being extremely busy at the National Hamfest last weekend I did manage to get hold of a dual band Yagi that was reasonably lightweight for hand held use and capable of being easily dismantled for transporting. (The Moonraker YG27-35 Dual Band) it has a single feed point and two adjustable gamma match sliders and was easy to adjust using my analyser.

It has a single feed and I tried it with the Baofeng and reception of the downlink was excellent, again on a couple of passes I tried answering calls with no success.

Last night I decided to try again but with the FT-857D set at 10W output. I put it on a small workbench in the garden and powered it from my portable SLA battery. I ran split operation with the 2m Tx VFO set at 145.850MHz with 67Hz CTCSS, the 70cm Rx VFO set at 436.800Mhz I was able to adjusted it down in 5kHz steps during the pass. I got the wife to take a picture while I was operating.

As I started to hear the downlink I heard Abdel M0NPT calling and answered him, I was shocked when he came back and we exchanging details - that was it I had made my first QSO via an amateur radio satellite! Then amazingly other stations started calling me and I was able to also work DO2SYD.

I did manage to record it on a small dictaphone (did have a bit of a brain fade with my callsign at one point!)

I could get hooked on this... There is also the new LilacSat-2 (CAS-3H) satellite with a FM transponder to try to work!So much to do, so little time...

Thursday, 1 October 2015

It has been five days since PINKY and PIGLET had their successful flight into the stratosphere. I have been studying the telemetry data and the photographs. I am really pleased with them but it makes the failure of previous Eggsplorer-1 mission to get any wow images more painful.

I checked out the telemetry statistics on http://habitat.habhub.org/stats/ and was impressed with the number of people who tracked (as can be seen in the pie chart below) I know that several interested parties have since visited the UKHAS wiki and have been asking questions on the IRC channel on how to do a flight and/or develop their own trackers. Naturally I have also been thinking about some possible future flights.

While the novelty of flying something into space, be it a toy pig or an egg is satisfying I would like to make any future flight serve some purpose, whether collecting more data or ideally doing some experiment with radio even if it within the constraints of the UK draconian regulations when operating in the air!

One set of data I did extract was the temperature profile during the flight. PINKY had two sensors, one internal to the Styrofoam box, the other external. PIGLET also had a temperature/pressure sensor but it was giving odd readings during the flight so have ignored that.

The graph shows internal/external temperature recorded by PINKY against altitude, there are two plots for each showing the ascent profile and the decent. The lowest temperature recorded by the external temperature was -49.5°C (-57.1°F) and the foam did a good job of insulating the internal electronics, though it drop below 0°C during the decent.

One thing I will do on the next flight (if it happens) is take a lot more photographs, using a 32GB memory card I could have held a lot more images. Also I will look at embedding the GPS coordinates (geotagging) into the image files.

I will also put on board a video camera, I did purchase a cheap dash cam type for £20 one off eBay for the Eggsplorer-1 but didn't use it because of sea-landing, I need to sort out powering it as the internal battery wouldn't last for the duration of the flight.

I have still to investigate the issues with the LoRa as to why it failed. This weekend Dave Akerman is flying three balloons in succession with LoRa tracker modules. They will be set up to work in a mesh, receiving and repeat each others telemetry. Sounds an interesting experiment, I will have to set my LoRa gateway back up and attempt to receive them.

Sunday, 27 September 2015

The National Hamfest high altitude balloon flew on Saturday and Pinky Pig reached a maximum altitude of nearly 26km (25,927m / 96,873 feet) as pictured above.

The flight originally planned for Friday had to be postponed due to wind direction and restrictions but I had sort approval for both days and was able to fly on Saturday. The conditions were perfect on launch day, clear blue sky with little cloud and almost no wind. Flight prediction put it landing around 25km away.

Both payload trackers worked flawlessly, PINKY the high speed RTTY successfully sent SSDV as well as telemetry and the backup tracker PIGLET sent the slow speed RTTY telemetry. Trackers from all over the UK as well as France, Holland and Poland received data and uploaded data to the UKHAS website.

The flight can be seen visualised in Google Earth below and while the 26km altitude was impressive it was around 4km less than I'd planned.

The launch certainly created a great deal of interest at the Hamfest, on the Friday we setup the club tent for South Kesteven ARS with a tracking station and demonstrated the payloads to interested visitors. Stewart (M0SDM) used his Land Rover with a push up mast for a pair of collinear X-50s so we could receive and decode. The mast and the Land Rover generated just as much interest.

Once filled to give the correct lift I sealed it off and checked everything was working then without a breath of wind slowly let the balloon rise, taking the weight of the payloads and once I was sure there were no aircraft flying nearby I let her go. The sky was clear and the balloon went up near vertically and could be seen for quite a long time as it ascended. Representatives of the RSGB and RadCom were in attendance to take photos and did a quick interview.

The tracking station was then full of people as the telemetry and pictures started to be received. It was great to see the huge interest in the balloon.

As the balloon started to near the planned maximum altitude I began to get ready to set off to recover it then suddenly I was told it had burst sooner than expected. I got a hurry up at which point the laptop and mobile connection decided to stop working! However I knew where to head off with my poor brother trying to sort it out as I drove.

Stewart telephoned and gave me directions of where the live prediction and tracking had put the landing spot. My wife also set off from home to come and assist. In the car we were receiving a signal but were struggling to decode and couldn't get on the internet to check the tracking.

I eventually pulled up near the landing zone, while trying to decode the weak signal another car pulled up with two radio amateurs who had been tracking the balloon. I was a little preoccupied and they eventually said they were off and wished us luck. I then realised we were the wrong side of the hill and turned around and drove up to the top and the signal strength increased.

Stewart had phoned to tell me to find the Viking way footpath, as we reached ground zero we saw the other amateurs car and they were setting off down the footpath! It was my flight I wanted to be the first to find it!

My wife then pulled up and was about to set off after them! Then I started getting successful decodes! With the new landing position in the GPS my wife raced off in hot pursuit as I sorted out the car and then followed her with my brother. It was a reasonable walk of around 800m and as we got near it became apparent the other team had been using the online tracker and had only got the last received position which had been sent from around 254m altitude. However the payload was still transmitting strongly and we were decoding it and it was reporting it was in fact at 115m altitude - they were therefore several hundred meters in the wrong direction.

Our accurate location gave us the edge and a quick hop up a bank into a stubble field and a 200m jog my brother spotted the parachute... we had found Pinky and Piglet and got there first!

I was surprised to find most of the balloon still attached, it hadn't so much burst as split in a single tear

The payloads had no damage, other than the antenna being bent by the landing

PIGLET had landed as planned and tested, I had put the battery pack at the top of the box the top heavy center of gravity causing it to roll on landing so the antenna would be upright. It was in a perfect orientation hence the strong signal.

The other chase team turned up and congratulated us then left... my apologies but I was in my own little happy place to be sociable. We then then had the obligatory team photograph before setting back to the Hamfest.

It has been an excellent experience and adventure. The pictures are better than I could have hoped for! Thanks to my understanding wife, my brother David and Stewart for setting up the antennas for the tracking station and manning it on his own while we went off to recover the payload.

Thanks to the organisers of the National Hamfest and Graham Boor (G8NWC) for asking me to do the flight and helping fund the venture and I hope it succeeded in publicising the event and the hobby.

Thursday, 24 September 2015

Given the latest flight path prediction, weather forecast and approval restrictions I will unfortunately have to likely postpone the National Hamfest high altitude balloon till Saturday.

The forecast for tomorrow is strong gusty winds at ground level which isn't ideal for launching, but that is the least of the issues.

The current flight predictions for tomorrow are not good. The prediction model used is accurate and for the size of balloon I have and the amount of helium at my disposal even a maximum fill giving the maximum ascent rate and assuming the calculated decent rate for the parachute it is still putting the likely landing right on the coast. Earlier in the week the landing wasn't quite as marginal but as the model's data set have been updated it has drifted further eastward, it is odds on it will actually land out to sea.

However the real show stopper was when I received the CAA approval for the launch this morning. They have put a restriction not permitting a launch if the balloon and payload is likely to go on a North Easterly or Easterly path that could interfere with operations on local military airfields.

This is the predicted flight path, generated by the CUSG Landing predictor at predict.habhub.org and the flight path currently goes directly over RAF Cranwell but not at a high enough altitude.

Flight prediction for Friday

Saturday is forecast to be a much calmer day with a predicted path as shown below

Flight prediction for Saturday

There would be no issues with the airfields for that flight path and has the advantage of going almost straight up and landing close by.

Apologies to those wanting to track on Friday, but the situation is out of my control and I would be foolhardy to ignore the prediction and it is very unlikely it will change significantly to allow a flight tomorrow so I hope you can all track on Saturday. I will still be at the Hamfest tomorrow with the equipment if you want to know more about what it is all about.

Tuesday, 22 September 2015

Not long now! Just three days left till the National Hamfest and hopefully the launch of my second high altitude balloon.

Balloon, parachute and helium have all been purchased and payloads have under gone final testing and have been put to one side ready for the flight which should hopefully be around 12pm on Friday 25th September.

They will transmit using the UKHAS telemetry protocol and can be tracked on tracker.habhub.org for information on how to receive and upload data to the tracking system visit the UKHAS wiki some information and useful links have been collated on the AMSAT-UK website

I was hoping to also transmit using the LoRa system, using the callsign PERKY. The transmitter had been successfully tested but a last minute gremlin has struck and it stopped working this weekend, I have been unable to locate the fault and suspect it is the actual module and with time being short have all but given up getting it working. If I do get it working it will be on 434.450MHz in Mode 1

PERKY seen working on SDR

PINKY & PERKY tracker

I have already detailed the PIGLET payload in an earlier post. The PINKY/PERKY payload is constructed on strip board and was originally meant to to be a prototype, hence the rubbish layout. I had planned to build a better laid out version but the tight time scale, stresses and demands of work, commitments with the radio club not to mention nursing the wife as she recovers from a major operation scuppered that plan. Being pragmatic I decided it didn't need to be work of art to work! I have secured all the connections with hot glue and it has been drop tested several times.

"Pinky" pig will be the passenger on the day, donning his fetching headset. Getting him in the right position for the camera was tricky.

I am still waiting for the CAA approval, should hopefully get it soon. I have put in a request for both days of the Hamfest just in case, the latest prediction at predict.habhub.org shows if I get the fill right I might just escape a watery landing on Friday, however Saturday looks more promising at the moment - also the forecast for Friday at the moment also has strong gusty surface winds, which could make the launch problematic. I am still planning for Friday since conditions and predictions do change.

Friday prediction as of 22/09/2015

Saturday prediction as of 22/09/2015

I and other members of South Kesteven ARS will be in attendance with a tracker station on the day, so please introduce yourself and perhaps join the club?